Generation5 JDK: The Basics

This article is intended for beginners who are unfamiliar with setting up
Java environments. As an example, let's look at how to run the
Generation5 JDK demonstrations. Firstly, all the
demonstrations require the individual Generation5 JDK CLASS files or JAR archive. The
CLASS files can be downloaded by going to the Generation5
JDK SourceForge page and downloading the latest source zip file. The latest JAR
file is always found at
http://www.generation5.org/jdk/bin/generation5.jar.
Note that this tutorial focuses on the Windows command-line, although the principles
within Linux remain the same.

Demonstrations

Setting up the Classpath

Whether you have downloaded the source or the JAR file, it must be placed in your
classpath. The classpath tells Java where to look for library files. Let's say
you have downloaded the Generation5 JDK source, and have unzipped it to a directory
called "G5JDK". To add the source to your classpath, type the following at the
command prompt:

set classpath=%classpath%;c:\g5jdk
- or -
set classpath=%classpath%;c:\g5jdk\generation5.jar

This appends the Generation5 JDK CLASS files or JAR to the current classpath
(%classpath%). More permanent methods of setting the classpath are available
but vary greatly according the OS you are using (even between Windows versions).

Running the Demonstrations

Demonstration programs are run using java, whereas applets are run using
appletviewer. For example:

The first line will run the CellDiagram
example, whereas the second line runs the
Kohonen
Applet. If you have problems getting these to run, check that a) java
and appletviewer are in your PATH (appletviewer is often not
included in the path by default) and b) classpath points to the Generation5
JDK CLASS files or JAR archive.

A few of the Generation5 JDK classes themselves have a main method that
can be called, whether it is simply a test or has some form of functionality. To run
these, you will have to call java something similar to:

java -cp %classpath% org.generation5.demos.Wolfram1DCA 3 126 480

Alternative Setups

To end this article, it is worth pointing out there are a few excellent
open-source Java IDE programs to help develop your applications or applets with the
JDK. Currently, I use NetBeans 3.6 which provides an excellent development
environment with integrated form designers, Javadoc, debuggers, code folding and a
lot more.

Conclusion

Remember that because Java is designed to work across many operating systems,
different hardware and as standalone application or as an applet. As such, it can be
very hard to setup especially from the commandline. If you have any problems, feel
free to contact me or post to the
Generation5 forums.